The Joint Collaborative Team on Video Coding (jct-vc) of itu-t wp3/16 and iso/iec jtc 1/sc 29/wg 11 held its second meeting during 21-28 July, 2010 at the itu-t premises in Geneva, ch

JCTVC-B102 [X. Zhao (CAS), L. Zhang, S. Ma, W. Gao (Peking Univ.)] Mode-dependent residual reordering for intra prediction residual

In this contribution, a mode-dependent residual reordering (MDRR) method is proposed to further simplify the mode-dependent directional transform (MDDT) for Intra coding. In the proposed MDRR, between the prediction and transform stages, a certain kind of reordering is implemented on the residual samples for each mode in spatial. The reordering is manipulated in a way that the distribution statistics of reordered residual samples present less mode-dependent characteristic. After the reordering, the nine Intra modes in I4MB and I8MB modes will be assigned into three groups, and only one transform matrix is assigned for each group. With the proposed MDRR, the number of transform matrices in MDDT is reduced from original 18, 18 and 8 to the proposed 3, 3 and 3 for I4MB, I8MB and I16MB, respectively. Experimental results show that, under the testing condition specified in the AhG report on alternative transforms with all-Intra conditions, compared with MDDT, average BD rate increase of 0.1% and BD PSNR drop of -0.005dB is observed.

Mode-dependent residual reordering.

Note 1: Similar approach as JCTVC-B039, but classification is different. Only 3 different transform bases and 3 scan directions are needed, performance increase compared to original MDDT 0.1% average.

Note 2: Similar classification scheme in JCTVC-B024

This contribution better fits to transform category.

Recommendation: TE establishment.